The more congested the network, the more fees you pay. Therefore, you must choose the appropriate times if you want to pay less fees.
Don't make the network more crowded, use
https://jochen-hoenicke.de/queue to find out the right fees and use this opportunity to get fast confirmations and small fees.
Right, also it's useful to monitor the live operations as it unfold (
https://blockchair.com/bitcoin/transactions) and on the basis of commissions for transactions in the current block to decide about fee for own transaction. The relatively low value of 15 sat/byte was succesfull for me last night. My transaction was in the block after around 40 minutes.